However, there's no option to resubmit available. I contacted TfL about this and they said:

Unfortunately as the card failed to collect the previous auto top up, this can no longer be added to the card. If you would like to set up auto top up again you will need to purchase a new Oyster card and this would need to be set up again.

I find it incredibly odd that they say it can be resubmitted online, but then don't offer the option (a bug?) and that I have to get a new card simply because I didn't collect it. Can't they just cancel the Auto top-up request on their system?

What I have read on some unofficial forums is that TfL stops Oyster cards where auto-top-up has failed and the card holder didn't respond to the email TfL sends about it. The card is permanently cancelled. I have not made an answer of this as I haven't yet found an official source. But supposedly you should be able to get any balance transferred to a new card at a ticket office.
– Michael HamptonApr 18 at 6:18

@JonathanReez Thanks for the info (I also use debit card for travel when appropriate), but it's not related to the question and doesn't apply to me in terms of the Oyster card itself.
– NeoApr 18 at 7:34

@JonathanReez That's categorically wrong for the reasons stated in the link you cited, and as I stated, it's not related to the question and doesn't apply to me in terms of the Oyster card itself.
– NeoApr 18 at 8:49